1. Technical Field
The present disclosure relates to a multi-directional switch device which performs a switching operation when both of two rubber contacts are pressed down to be turned on, and is very suitable as, for example, a mirror angle control switch of a vehicle.
2. Related Art
As multi-directional switch devices, for some time, a four-directional switch device having a contact structure shown in FIG. 5 has been known (for example, refer to Japanese Unexamined Patent Application Publication No. 08-287787). In FIG. 5, a contact sheet member 21 is placed on a circuit board 20. The contact sheet member 21 is obtained by forming swollen rubber contacts 22 in a protruding manner at a plurality of positions of an electrically insulated elastic sheet formed of silicon rubber, and a movable contact 22a is provided inside each of the rubber contacts 22. Although the two adjacent rubber contacts 22 are shown in FIG. 5, eight rubber contacts 22 are dispersed in a protruding manner on the substantially same circumference of the contact sheet member 21, and the movable contact 22a of each of the rubber contacts 22 is opposite each of fixed contacts 23 installed on the circuit board 20 so as to be movable close thereto or away therefrom. Generally, when a top portion 22b of the rubber contact 22 is pressed down by a predetermined stroke, a skirt portion 22c is buckled and deformed (reversed) to generate a click feeling, and the movable contact 22a comes into contact with the fixed contact 23 to be turned on.
In addition, in FIG. 5, a driving body 24 or a pressure body 25 is disposed as an actuator for pressing and driving the rubber contact 22. The position of the driving body 24 is regulated by a guide wall 26 which is integrated with a housing (not shown). The pressure body 25 is mounted onto the top portion 22b of the rubber contact 22, and the pressure body 25 is pressed down by the driving body 24. That is, when a user presses down an operation member (not shown) in a desired direction, since the driving body 24 located in the desired direction is pressed down, the pair of rubber contacts 22 selected in response to the operation direction is pressed down by the pressure body 25. Since all of the rubber contacts 22 are formed in the same shape, the pair of pressed rubber contacts 22 generates a click feeling at almost the same time, and is turned on. When the pair of two rubber contacts is electrically connected to the corresponding fixed contacts 23, a predetermined switching operation is performed.
Accordingly, the user is able to selectively perform four types of different switching operations in response to a direction in which the operation member is pressed down. For example, in the case of a mirror angle control switch of a vehicle, the user is able to change a mirror in a desired direction (any one direction in the up/down and left/right directions) by pressing down the operation member in the desired direction. In addition, when the operation force is removed, since the buckled and deformed skirt portion 22c returns to its original shape due to its elasticity, the movable contact 22a is separated from the fixed contact 23 so that the rubber contact 22 is automatically turned off. Accordingly, the driving body 24 or the pressure body 25 is lifted up to the original height position.
However, in the multi-directional switch device of the related art adopting the contact structure shown in FIG. 5, when the height positions of the pair of two rubber contacts 22 in a non-operation state are not equal to each other due to a variation in manufacture, one rubber contact may be buckled and deformed (reversed) earlier than the other rubber contact in an operation state. In addition, even when the height positions of the two rubber contacts 22 in a non-operation state are set to be equal to each other, if the user presses the edge thereof so that an operation force is applied to a position close to any one of the rubber contacts, the other contact may be buckled and deformed earlier than the one rubber contact. Likewise, even when there is a difference in the reversing timing of the pair of two rubber contacts 22, a small difference in time does not cause a problem if the operation force is strong. However, if the operation force is weak, there is a possibility that the operation force for the operation member is removed at the point in time when the user feels the click feeling generated from the one rubber contact buckling and deforming at the first time. In this case, since the other rubber contact is not turned on, the switching operation is not performed.
Therefore, when the reversing timings of the pair of two rubber contacts 22 are deviated from each other in a contact structure shown in FIG. 5, an erroneous operation easily occurs, which leads to deterioration in operability and the user's mistake on the judgment of malfunction of the contact. In addition, if the operation force is strong, even when the normal operation state is perceived, since the click feeling is intermittently generated, the operation feeling becomes worse.